The present invention relates to a key slot device of an in-vehicle auxiliary key, into which is inserted an auxiliary key that is kept in a vehicle as a vehicle key (in which the key is set), and more particularly, to a key slot device of an in-vehicle auxiliary key that retains an auxiliary key locked therein until the auxiliary key is permitted to be lent.
Various types of vehicle lending systems have been conventionally invented that allow a vehicle to be lent under a restricted use condition to a third person. This is because if a vehicle is lent to a third person in a state where the vehicle can be used without restriction, the borrower may use the vehicle at his/her discretion. Japanese Laid-Open Patent Publication No. 2004-25936 discloses one example of such a vehicle lending system employing restricted use conditions. In the publication, no restriction is placed on the vehicle when the vehicle is operated using a master key, and a restricted use condition is employed when the vehicle is operated using a sub-key. When lending the vehicle, the sub-key is handed to a borrower, so that the borrower can use the vehicle under a restricted use condition.
The vehicle lending system of the above publication requires the user to carry a master key and a sub-key. This increases the number of articles a user needs to carry, making it inconvenient for the user. Also, if the user needs to lend the vehicle to a third person when not carrying the sub-key, he/she must go get the sub-key from the place where it is kept. This also makes it inconvenient for the user.
Other types of restricted condition vehicle lending systems include, for example, an assist key system. The assist key system includes a vehicle key (hereinafter, referred to as an assist key), which is used only when the use of the vehicle is restricted, and is installed in the vehicle in advance. When lending the vehicle to a third person, the user lends the assist key so that the vehicle can be used only under restriction. The assist key functions as a type of sub-key as described above, and has a key code for restricting the use of the vehicle. This eliminates the necessity for carrying two types of vehicle keys, and thus increases convenience.
The assist key of the assist key system is placed, for example, in the glove compartment of the vehicle. For example, a key slot is installed in the glove compartment and the assist key is inserted into the key slot and kept therein. If the assist key inserted in the key slot can be freely removed therefrom, anybody can freely take the assist key and use the vehicle. This lowers the security level against key theft. Therefore, the assist key system preferably includes in the key slot a key retaining device (key lock device) that is capable of locking the inserted assist key into the key slot. In this case, when the assist key is permitted to be lent, the key retaining device is unlocked, which allows the assist key to be removed.
In some cases, instead of properly returning assist key to the key slot, some people tamper with the key slot by putting a foreign object or a finger into the key slot. If the key lock device is locked with a foreign object inserted, the foreign object gets caught in the device and may cause a breakdown of the device. There has therefore been a demand for a technology that does not activate the key lock device in such cases.